WordPress.org

Using FTP

* download the plugin to your local computer
* Extract the plugin archive
* ftp the entire livepress/ directory to your wordpress plugin directory
* Go to your plugins admin page and activate the LivePress plugin
* Go To the Settings -> LivePress to configure your plugin on the admin page 

Using shell access

* cd to your wp-contents/plugins directory of your wordpress installation
* download the plugin archive directly
* wget http://livepress.googlecode.com/files/livepress_2.x.x.tar.gz
* untar the files
* tar -xvzf livepress_2.x.x.tar.gz
* If you ran this as root, you may need to fix file ownerships
* chown -R <wpuser> livepress
* again, check file ownership
* Go to your plugins admin page and activate the LivePress plugin
* Go To the Settings -> LivePress to configure your plugin on the admin page